Refrigerating apparatus



Dec. 6, 1960 R. D. HElTcHuE, SR 2,963,216

REFRIGERATING APPARATUS Filed Oct. 9, 1958 EVAPORATOR CONDENSER \NVENTORREGlS D. HEI CHUE SR.

ATTORNY United States Patent() 2,963,216 yHarmonRATING APPARATUS RegisD. Heitchu'e, Sr., Longmeadow, Massa, assignor to Westinghouse ElectricCorporation; East Pittsburgh, Pa., a corporation of Peurxsylv-im'iaVFiled Oct. 9, 19,58, `Sel' No.. 766,247 6 Claims. (Cl. 230-58)"V ThisinventionV relates to a motor-,compressor unit `for refrigeratingsystems and particularly to a unit resiliently supported in a Huid-tightcasing and wherein the motor is cooled by refrigerant vapor Vflowing tothe compressor.

The objective of the invention is improved performance of themotor-compressor unit, and this objective is achieved by the use of anovel arrangement for confining and directing vaporous refrigerant overcertain portions of the motor-compressor unit and away from otherportions of `said unit on itsy way to the inlet of the compressor.

In accordance with the invention, that endof the motor which is notenclosed by a frame is enclosed by a cover or hood that is incommunication with the com pressor inlet through a tube. This cover isdisposed close to the wall of the motor-compressor casing, which isprovided with means for returning vaporous refrigerant to the casing.The cover has an inlet opening therein through which refrigerant, andparticularly the cool refrigerant vapor entering the motor-compressorcasing, is drawn by the compressor. The cover, in cooperation with themotor-compressor frame, contines refrigerant ow over and around themotor components, for the purpose of cooling the motor, and directs themain body of refrigerant ow away from other Warm portions of themotor-compressor unit, such as the compressor cylinder, the hot gasdischarge line, and the pool of lubricating oil in the casing.

The invention affects the operation of the motorcompressor unit in twoways, each ofwhich increases the pumping capacity of the unit. In thefirst place, the motoris cooled more effectively, enabling the motor tocarry increased loads without overheating. Secondly, cooler, andconsequently more dense, refrigerant' vapor is delivered to thecompressor inlet, so that a greater quantity of refrigerant iscompressed with each stroke of the compressor piston.

Other objects, advantages and features of the invention will beyapparent from the following detailed description in which reference ismade to the accompanying drawings forming a part hereof, and wherein:

Fig. 1 shows diagrammatically a refrigerating system incorporating amotor-compressor unit constructed inaccordance with this invention, theunit being shown in vertical section; and,

Fig. 2 is a plan view of the unit with the top of the casing removed.

The motor-compressor unit referred to generally by the reference numeral1Q is a `part of a refrigerating system which also includes a dischargeconduit 11, a condenser 12, an expansion device 13, an evaporator 14 anda suction conduit 15. The expansion device 13 may be of any suitabletype known inthe art, such as a capillary ktube or a thermostaticexpansion valve.

The refrigerating system as a whole operates in the usual manner of suchapparatus,-the refrigerant gas compressed by the motor-compressor unit10 being conveyed 2,963,216` Patented Dec.`6, 1960 ICC 2 through thedischarge conduit 11 to the condenser 12, wherein the same is condensed.The liquefied refrigerant then ows. through the expansion devicel 12which reduces theL pressure thereof. In the evaporator 14, the liquidrefrigerant is vaporized by heat extracted from the substance to becooled and the vaporized refrigerant flowsthrough the suction conduit 15to the motor-compressory unit, wherein the same is re-compressed andrecirculated.

The motors-compressory unit 10 includes a compressor 16, as motor 17 anda frame 18 for maintaining the compressor and the motor in operativerelation to one another. The frame also provides bearing supports forthe movable elements of' the motor and the` compressor. The compressor,the motor and the frame are resiliently supported within a uidftightcasing 19 on three helical springs 20, one ofv which is illustrated inFig. l. The springs 20 are of a compression type and are disposedvertically between casing mounted brackets 21 and lugs 22 projectingoutwardly from the frame 1'8.

The motor 17 comprises a rotor 23 mounted on a kvertical axis shaft 24and a stator 25 having windings 26 projecting from opposite endsthereof. The stator 25 is received in a tubular portion 27 of the frame18 and is secured in place therein by a clamping ring 28 which issecured to the frame"18 by several bolts 29. The bolts 29 also passthrough the rim of a cup-shaped cover or hood 30 which encloses the endof the stator 25 and the windings 26 thereon which are not enclosed bythe tubular portion 27 of the frame 18. The other end of the stator 25,i.e., the end near the compressor 16, is

at least partially enclosed by the frame 18, although there are one ormore openings 31 provided in this region of the frame 18 which allowlubricating oilto drain from the frame into the bottom of the casing 19which forms a reservoir for lubricating oil.

The compressor 16 is driven by the motor 17 through shaft 24 which hasan eccentric 32 thereon near its lower end. The eccentric 32 impartsreciprocating motion to a connecting rod 33 and a piston 34, the latterof which moves in a cylinder 35 formed as a part of the motorcompressorframe 18. The piston 34, in moving back and forth in the cylinder 35,draws vaporous refrigerant into the compressor 16 through an inlet pipe36 and discharges compressed refrigerant through the discharge line 11which extends through the wall of the casing 19. The inlet pipe 36connects the inlet of the compressor 15 with the interior of the cover30 enclosing the remote end of the motor 17.

The suction conduit 15 of the refrigerating system extends through adepressed region 37 in the top wall of the casing 19 and admitsrefrigerant to the interior of the casing. `This cool refrigerant isutilized for cooling the motor 17 and is drawn` by the compressor 16through an inlet opening 38 provided in the cover 30, over the endwindings 26 at the upper end of the motor, and over portions of therotor 23 and stator 25 of the motor before entering the inlet pipe 36.

It will be noted that, although there is no direct connectionbetween'the suction conduit 15 and the compressor inlet pipe 36, i.e.the conduit is independent of the motor cover 30, and though the entire`internal volume ofl the motor-compressork casing 19 is atksubstantiallycompressor inlet pressure, the cool incoming refrigerant is made to owover portions of the motor 17 and then directly into the compressor 16without ,being given the opportunity to come in contact with other warmportions of the motor-compressor unit, such as the compressor cylinder35, the discharge line 11 which contains hot compressed gas, and thepool of oil in the bottom of the casing 19. The motor 17 is thuseffectively cooled and the pumping capacity of the compressor 16 isincreased because the compressor is handling cooler and, consequently,more dense refrigerant vapor than it would if the refrigerant wereiirst'warmed by contact with the above-mentioned warm portions of theunit.

Several detailed features which contribute to the overall improvedperformance of the motor-compressor unit are embodied in the unitillustrated in the drawing. One of these features concerns arelationship between the motor end cover 30 and the adjacent wall of themotor-compressor casing 19. Preferably, the motor and compressor are sosupported in the casing 19 as to dispose the cover 30 in closely spacedrelation to the wall of the casing 19 through which vaporous refrigerantenters from the suction conduit 15. It will also be noted that thecentral wall portion of the cover 30 is depressed to conform at leastpartially to the depressed region 37 of the wall of the casing 19. Thisdepression in the cover 30 is effective to guide refrigerant issuingfrom the suction conduit into the inlet opening 38 in the cover. Inaddition, this cover configuration provides an annular recess 39 on theinside cover 30 which at least partially receives the windings 26 at theremote end of the stator 25. This annular recess 39 functions as arestricted flow passage for confining the ow of cool vaporousrefrigerant closely about the windings 26 of the stator.

It will also be noted that the compressor inlet pipe 36 is connected toa peripheral, or side wall, region of the motor end cover 30 so thatrefrigerant must ow over and around the stator windings 26 beforeentering the inlet pipe.

It can be readily appreciated that the cover inlet opening 38 ispreferably made larger than the area of the suction conduit 15 at itsdischarge end to insure that the major portion of the refrigerantissuing from the suction conduit 15 will find its way through theopening 38 into the area beneath the cover 30. The supporting springsfor the motor 17 and the compressor 16 permit movement and vibration ofthese components of the unit when the unit is operating, so there isrelative movement between the inlet opening 38 and the discharge end ofthe suction conduit 15. For this reason, the inlet opening 38 ispreferably shaped like the vibration or movement pattern of this end ofthe motor 17 so that there will always be at least a part of the opening38 opposite the discharge end of the suction conduit 15 during operationof the unit.

From the above description it will be seen that this invention providesa relatively simple and inexpensive arrangement for insuring effectivecooling of the motor of a motor-compressor unit that is resilientlysupported within an enclosing casing. Moreover, the provision of anefficient flow path for the motor cooling refrigerant enables thecompressor to work with cooler refrigerant and, consequently, pump agreater quantity of refrigerant.

While the invention has been shown in but one form, it will be obviousto those skilled in the art that it is not so limited, but issusceptible of various other changes and modifications without departingfrom the spirit thereof.

What is claimed is:

1. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for driving the compressor, said motorincluding a rotor and a stator, a frame for supporting said compressorand said motor in operative relation to one another, said frameincluding a portion adapted to receive said stator in a manner to atleast partiallyI enclose the end of the stator near the compressor andto expose the end of the stator remote from said compressor, a cover forthe exposed end of said stator `and the corresponding end of said rotor,said cover having a refrigerant inlet opening therein, tubular meansproviding communication between the interior of said cover and the inletof said compressor, a common fluid-tight casing for the compressor, themotor and the frame, means for resiliently supporting said frame in saidcasing, and means independent of said cover for admitting vaporousrefrigerant to the interior of said casing in the vicinity of the inletopening in said cover.

2. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for ldriving the compressor, said motorincluding a rotor and a stator, a frame for supporting said compressorand said motor in operative relation to one another, said frameincluding a portion adapted to receive said stator in a manner to atleast partially enclose the end of the stator near the compressor and toexpose the end of the stator remote from said compressor, a cup-shapedcover secured to said frame for covering the exposed end of said statorand the corresponding end of said rotor, said cover having a refrigerantinlet opening therein, tubular means providing communication between theinterior of said cover and the inlet of said compressor, a commonfluidtight casing for the compressor, the motor and the frame, means forresiliently supporting said frame in said casing, and means provided ina wall of the casing near the inlet opening in said cover andindependent of said cover for admitting vaporous refrigerant to saidcasing.

3. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for driving the compressor, said motorincluding a rotor and a stator, a frame for supporting said compressorand said motor in operative relation to one another, said frameincluding a portion adapted to receive said stator in a manner to atleast partially enclose the end of the stator near the compressor and toexpose the end of the stator remote from said compressor, a cup-shapedcover secured to said frame for covering the exposed end of said statorand the corresponding end of said rotor, said cover having a refrigerantinlet opening in a central wall portion thereof, tubular means providingcommunication between the interior of said cover and the inlet of saidcompressor, a common Huid-tight casing for the compressor, the motor andthe frame, means for resiliently supporting said frame in said casingwith said cover in closely spaced relation to a wall of said casing, andmeans provided in said wall of the casing near the inlet opening in saidcover and independent of said cover for admitting vaporous refrigerantto said casing.

4. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for driving the compressor, said motorincluding a rotor and a stator having windings extending from oppositeends thereof, a frame for supporting said compressor and said motor inoperative relation to one another, said frame including a portionadapted to receive said stator in a manner to at least partially enclosethe windings at the end of the stator near said compressor and to exposethe windings at the end of the stator remote from said compressor, acup-shaped cover mounted on said frame and having said exposed windingsof said stator disposed therein, said cover having a refrigerant inletopening in a central wall portion thereof, tubular means connecting theinlet of said compressor to said cover in a peripheral region of saidcover, whereby vaporous refrigerant entering said inlet opening in saidcover is confined to ow around and in contact with said exposed statorwindings in passage to the inlet of the compressor, a common fluid-tightcasing for the compressor, the motor and the frame, means forresiliently supporting said frame in said casing, and means independentof said cover for admitting vaporous refrigerant to said casing near theinlet opening in said cover.

5. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for driving the compressor, said motorincluding a rotor and a stator having windings extending from oppositeends thereof, a Iframe for supporting said compressor and said motor inoperative relation to one another, said frame including a portionadapted to receive said stator in a manner to at least partially enclosethe windings at the end of the stator near said compressor and to exposethe windings at the end of the stator remote from said conlpressor, acup-shaped cover having an inwardly depressed central wall portionproviding an annular recess in said cover, said cover being mounted onsaid frame and having said exposed'windings of said stator disposed atleast partially within said annular recess, said cover having arefrigerant inlet opening in said central wall portion thereof, tubularmeans connecting the inlet of said compressor to said cover in aperipheral region of said cover, whereby vaporous refrigerant enteringsaid inlet opening in said cover is confined to flow around and incontact with said exposed stator windings in passage to the inlet of thecompressor, a common fluid-tight casing for the compressor, the motorand the frame, means for resiliently supporting said frame in saidcasing, and means for admitting vaporous refrigerant to said casing nearthe inlet opening in said cover.

6. An enclosed motor and compressor unit for a refrigerating systemcomprising a compressor, a motor for driving the compressor, said motorincluding a rotor and a stator having windings extending from oppositeends thereof, a frame for supporting said compressor and said motor inoperative relation to one another, said frame including a portionadapted to receive said stator in a manner to at least partially enclosethe windings at the end of the stator near said compressor and to exposethe windings at the end of the stator remote from said compressor, acup-shaped cover having an inwardly depressed central wall portionproviding an annular recess in said cover, said cover being mounted onsaid frame and having said exposed windings of said stator disposed atleast partially within said annular recess, said cover having arefrigerant inlet opening in said central Wall portion thereof, tubularmeans connecting the inlet of said compressor to said cover in aperipheral region of said cover, whereby vaporous refrigerant enteringsaid inlet opening in said cover is confined to ow around and in contactwith said exposed stator windings in passage to the inlet of thecompressor, a common fluid-tight casing for the compressor, the motorand the frame, means for resiliently supporting said frame in saidcasing with said cover in closely spaced relation to a wall of thecasing, and means provided on said wall of the casing for admittingvaporous refrigerant to said casing near the inlet opening in saidcover.

References Cited in the tile of this patent UNITED STATES PATENTS2,274,942 Touborg Mar. 3, 1942 2,286,272 Higham lune 16, 1942 2,306,608Hubacker Dec. 29, 1942 2,741,425 Scheldorf Apr. 10, 1956

